Combined dust cap and valve cap



Jan. 8, 1929.

1,698,503 H..P. KRAFT -COMBI-NED DUST CAP AND VALVE CAP Ongmal Flled May 9, 1923 INVENTOR By Attorneys,

Patenteddan. 8, 19259.

UNITED sr teasers HENRY PHILLIP KRAFT, or nrnenwoon. new annsnv; EDGAR J. rnitnlrsnnn EARL A. nAnn, nxnou'rons on THE'WILL on nnnnv Keane, DECEASED, assrenons'ro A. scnnannns son, rnconnonnrnn, or naoonn z'iv. new YonK, A CORPORATION OF NEW YORK.

COMBINED DUST GAP AND VALVE CAP.

Application filed May 9, 1923, Serial No. 837,672. Renewed July 7, i

This inventionrelates to a combined dust dust cap. This relationship between the dust 7 cap and valve cap was brought about by said.

' caps having similarpolygonal or other noncircular cross sectional contours. In such constructions, however, it was found that owing to the leverage action existing between the dust cap and valve cap, too great a turning force was usually communicated to the valve cap in the'course of applying the caps to the valve casing. The strain upon the packing gasket brought about in this way frequently injured the gasket to such extent as to render it ineffective as a check against leakage through the valve. 7

According to'the' present invention the aforementioned and other disadvantages inherent in devices of the character described are entirely overcome. ThisI accomplish by making the dust cap and valve cap relatively rotatable and introduce suflicient friction between the two to enable the dust cap to screw down the valve cap upon thevalve stem or the like with enough force to make a tight joint bet-ween the valve cap washer and the valve stem. I preferably accomplish this result by having the valve cap relatively slidable-and rotatable within the dust cap and employing a single frictional means between the two caps, preferably in the form of splitspring ring, for holding the valve cap against both rotative and longitudinal action 7 when there is no strain tending to displace it.

The invention also includes other features of novelty which will be hereinafter more fully set forth.

In the accompanying drawing wherein I have shown-two embodiments of my invent1on,

Figure 1 shows an embodiment of the invention in longitudinal section, the top of the dust cap being shown in elevation.

Fig. 2 is a transverse section taken on the line 22 of Fig. 1.

Fig. 3 is a perspective view of a detail of the invention.

Fig. 4 is a view similar to Fig. 'l, showing a modification.

Fig. 5 is a sectiontaken on the line 5 5. of

Fig. 4, and

Fig. 6 is a perspective view of a detail shown inthe modified form of the invention. Referr ngto Figs. 1 to 3 of the drawings,

let A indicate the combineddust cap'andv;

valve cap as a. whole which comprises the dust cap member Band the valve capv member C. The dust cap as herein shown consists of a hollow shell of circular cross section open at one end andclosed at its otherend,,which 12- .latteris preferably formed with a screwdriver projection D for removing. the valve insides from a tire valve casing. The 'valve cap C as hereln shown consists of abody portion E ofeircular cross section adapted for.

sliding and rotational movement with respect to the dust cap, and an internally threaded skirt vportion F of smaller diameter than i the body portion adapted for screw threaded engagement with the end of a valve casing.

,According to the present invention; rotational movement is communicated to" the valve cap by the dust cap through the medium of a frictional means on thevalve cap engaging the interior wall of the dust cap. Said. frictional means is preferably so constituted as to permit'both cap members to be'rotated a unit until the frictional resistance. be-

tween the two is reduced to a point where. one of the caps can he slipped completely around the other upon continuing the turning force. According to the present disclosure said frictional means'has the form of a split spring ring H seated in a groove 1 on the bodyportion of the valve cap. The ends of the spring are preferably bent upward at right angles to the plane of the ring and seat in a recess J on the valve cap body. These longitudinal portions of the ringprovide increased frictional engagement with the dust cap tending to retard relative rotation between the two caps. To further increase the frictional entuted, it will be understood, is at all times adapted for. slidable action longitudinally of the dust cap and for relative rotational movement with respect to the dust cap only after ,the packing gasket G engages the top of the valve casing, which engagement is sufiicient to permit the slip-frictional rotatlon of the dust cap around the valve cap. To prevent the withdrawal of the valve cap from the dust cap during the act of removing caps from a valve casing, the open end of the dust cap L 1s turned inwardly to overlap the body portion E of thevalve cap.

In the modification shown in Figs. 4 to 6, the dust cap instead of being of circular cross section has its .wall fluted to provide a series of longitudinal grooves M, the function of which is to provide additional frictional engaging surface for the longitudinal portions of the split ring, thus further insuring cooperative'rotational 'movement between the the dust cap the valve cap is screwed home upon the casing. Uponfurther turning the dust cap it will be found to slip around the valve cap and may then be pushed downwardly to. engage the rim nut or felloe of the wheel.

The slip frictional engagement between the dust cap and valve cap insures against a strain being applied to the packing gasket sufficient to injure same, as is possible in the constructions heretofore proposed wherein the valve cap and dust cap are not relatively rotatable. The device may be removed from the valve 'casingby either reversing the preceding operationsor by merely turning the dust cap to theleft to unscrew the'valve cap. By employing the latter method the valve cap will be found to occupy a definite position within the dust cap, such that in subsequent applications of the device a mere turning of the dust cap to the right will sulfice to apply both caps. The frictional engagement between the valve cap and dust cap, it will be understood,

is at all times sufficient to insure against accidental relative longitudinal movement, as for example, by the careless pushing of the dust cap over the valve casing in the course of-applying the same.

. By the present inventionI am enabled to screw down the valve cap to an extent which prevents the over-straining of the washer and its rapid destruction, it being impossible to tighten the cap any more than is permitted by the frictional retardation of the valve cap in the dust cap, so that the latter by its greater diameter and nanipulating surface cannot be used to destroy the valve cap washer.

l/Vhile I have shown and described the preferred embodiments of my invention, it will be understood that I do not wish to be limited to the specific disclosure, since various changes may be made therein without departing from the spirit of the invention.

What I claim is: v

1. In combination, a dust cap, a valve cap and co-operating frictional means on said caps,.said frictional means comprising a split spring ring having a portion thereof extending in a direction circumferentially' of the caps and a portion extending longitudinally of the caps.

2. In combination, a dust cap having inter- 7 mil longitudinal grooves, a valve cap slidable in said dust cap and frictional means'on the valve cap adapted to engage in said grooves to provide a slip frictional engagement be tween the caps to permit them to'be rotated as a unit orrelatively to each other.-

3. In combination, a dust cap having internal longitudinal grooves, a valve cap slidable in said dust cap and the valve cap having a split spring ring having parts adapted to engage in said grooves to provide a slip frictional engagement between the caps to permit them to be rotated as a unit or'relatively to each other. 4:. In combination, a dust cap having a noncircular contour and a valve cap slidable and rotatable within said dust cap, said valve cap having a recess, spring means in said recess, and a member having aworking face to fit the internal contour of the dust cap held in contact therewith by said spring means...

In witness whereof, I have hereunto signed my name. I

HENRY PHILLIP K AFT. 

